Microelectromechanical systems (MEMS) devices are micro-sized devices or machines having stationary and/or movable elements that provide some types of electro-mechanical functionality. MEMS devices may fall in a range from less than 1 micron to several millimeters in size. MEMS devices may be constructed on a silicon substrate or wafer by using various fabrication techniques such as bulk micromachining of the silicon substrate itself and/or surface micromachining. The surface micromachining may involve building microstructures on a substrate using various semiconductor integrated circuit (IC) fabrication technologies such as material deposition, patterned photolithography, and etching.
MEMS devices can be incorporated into IC devices, such as complementary metal-oxide-semiconductor (CMOS) devices. CMOS-MEMS integration can improve device performance, allows for smaller packaging, and reduces manufacturing costs. The CMOS-MEMS integration is generally performed at chip level. In some instances, the CMOS chip may be an application-specific integrated circuit (ASIC) chip which is generally classified as a chip (IC) that is custom built for a specific end use or purpose. One type of ASIC chip is a system-on-chip (SoC) which includes a processor, memory devices, and other ancillary components, built on an application specific chip. Some MEMS devices which may be found in a semiconductor chip package include, for example without limitation, micro-timing devices, micro-sensors, micro-actuators, accelerometers, micro-switches, micro-pumps and valves, and others that support and assist with controlling the functionality of the chip(s) in the package and/or system-level IC.